Feature Request: Copy/insert citekey (not full bibtex)

[stefan2904]

First, thanks for the beautiful package!

I often query for papers on DBLP, and my use case involves inserting just the citekey without downloading the full bibtex code to a file.

What I would like to be able to do with biblio is the following:

1.) Start a lookup, e.g. biblio-dblp-lookup
2.) Search for a paper
3.) Select the paper
4.) Hit a key, let's say k
5.) Have the citekey of the selected paper inserted and/or added to the kill-ring (like i/c do with the bibtex code)

For DBLP, this could be done by using the key field of the search-result entries directly, without even loading the bibtex code. I noticed the Adding new actions section in the readme, but from what I understand this actions are only executed after the bibtex code is loaded (correct me if I am wrong). Also, the biblio-dblp--extract-interesting-fields function that extracts the interesting fields from the DBLP currently does not extract the key field of the entries (which could be used to generate the DBLP: citekeydirectly).

For other backend I am not sure if all of them return the citekey in the result and thus it probably could be necessary to parse the bibtex (not sure if this is not done anyway as citekeys are customizable).